Rooney joined CBS in 1949, as a writer for the show Arthur Godfrey's Talent Scouts. The program was a hit, reaching the number one position in the ratings in 1951.

Rooney wrote his first television essay in 1964, called "An Essay on Doors." His famous end-of-show essay, "A Few Minutes With Andy Rooney" on 60 Minutes, began in 1978.

Rooney is best known for a 1990 commentary that had him suspended from the show for three months, saying that, "Too much alcohol, too much food, drugs, homosexual unions, cigarettes [are] all known to lead to premature death." He later expressed his remorse by saying, "There was never a writer who didn't hope that in some small way he was doing good with the words he put down on paper and, while I know it's presumptuous, I've always had in my mind that I was doing some little bit of good. Now, I was to be known for having done, not good, but bad. I'd be known for the rest of my life as a racist bigot and as someone who had made life a little more difficult for homosexuals. I felt terrible about that and I've learned a lot."

He later came under fire for comments made after Nirvana singer Kurt Cobain committed suicide. In a string of comments about the singer, he stated, "If [Cobain] applied the same brain to his music that he applied to his drug-infested life, it's reasonable to think that his music may not have made much sense either."